rust: device: Move property_present() to FwNode

The new FwNode abstraction will be used for accessing all device
properties.

It would be possible to duplicate the methods on the device itself, but
since some of the methods on Device would have different type sigatures
as the ones on FwNode, this would only lead to inconsistency and
confusion. For this reason, property_present is removed from Device and
existing users are updated.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Remo Senekowitsch <remo@buenzli.dev>
Link: https://lore.kernel.org/r/20250611102908.212514-4-remo@buenzli.dev
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

drivers/cpufreq/rcpufreq_dt.rs

@@ -20,7 +20,8 @@
 /// Finds exact supply name from the OF node.
 fn find_supply_name_exact(dev: &Device, name: &str) -> Option<CString> {
     let prop_name = CString::try_from_fmt(fmt!("{}-supply", name)).ok()?;
-    dev.property_present(&prop_name)
+    dev.fwnode()?
+        .property_present(&prop_name)
         .then(|| CString::try_from_fmt(fmt!("{name}")).ok())
         .flatten()
 }

rust/kernel/device.rs

@@ -6,7 +6,6 @@
 
 use crate::{
     bindings,
-    str::CStr,
     types::{ARef, Opaque},
 };
 use core::{fmt, marker::PhantomData, ptr};
@@ -219,12 +218,6 @@ pub fn fwnode(&self) -> Option<&property::FwNode> {
         // defined as a `#[repr(transparent)]` wrapper around `fwnode_handle`.
         Some(unsafe { &*fwnode_handle.cast() })
     }
-
-    /// Checks if property is present or not.
-    pub fn property_present(&self, name: &CStr) -> bool {
-        // SAFETY: By the invariant of `CStr`, `name` is null-terminated.
-        unsafe { bindings::device_property_present(self.as_raw().cast_const(), name.as_char_ptr()) }
-    }
 }
 
 // SAFETY: `Device` is a transparent wrapper of a type that doesn't depend on `Device`'s generic

rust/kernel/device/property.rs

@@ -8,6 +8,7 @@
 
 use crate::{
     bindings,
+    str::CStr,
     types::{ARef, Opaque},
 };
 
@@ -56,6 +57,12 @@ unsafe fn from_raw(raw: *mut bindings::fwnode_handle) -> ARef<Self> {
     pub(crate) fn as_raw(&self) -> *mut bindings::fwnode_handle {
         self.0.get()
     }
+
+    /// Checks if property is present or not.
+    pub fn property_present(&self, name: &CStr) -> bool {
+        // SAFETY: By the invariant of `CStr`, `name` is null-terminated.
+        unsafe { bindings::fwnode_property_present(self.as_raw().cast_const(), name.as_char_ptr()) }
+    }
 }
 
 // SAFETY: Instances of `FwNode` are always reference-counted.